Multi-language support in desktop application development requires careful planning and consideration. It involves various considerations such as internationalization, localization, user interface design, data storage, and testing. Internationalization involves designing and developing the application in a way that supports multiple languages and cultures. Localization involves translating the application into different languages and adapting it to specific cultural norms. User interface design should consider text expansion, proper formatting, and character encoding to accommodate different languages. Data storage should support Unicode and be flexible enough to handle different language requirements. Testing should include checking for language text display, input validation, and language-specific functionalities. Overall, multi-language support requires a combination of technical expertise, cultural understanding, and attention to detail.